Submarine-sound detector



T. BODDE.

SUBMARINE SOUND DETECTOR. APPLICATION FILED SEPT.2. I916.

Patented Mar. 15, 1921.

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" UNITED STATES PATENT OFFICE.

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SUBMARINE- SOUND DETECTOR.

. Specification of Letters Batent.

Application filed September 22,1916. Serial 110. 118,184.

To all whom it may-0012mm:

Be it knownthat I, THEODORE Bonnn, a subject of the Queen of The Netherlands, residing at Lynn, in the'county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Sub-' marine-Sound Detectors, of which-the fol lowing is a specification.

This inventionrelates to submarine sound detectors, and has particular application to .is exceedingly sensitive or responsive to sounds or tones, and which possesses a, relatively wide range of action, so that any sounds or tones, whether weak or strong, or of different pitch, which are emitted under the water may be instantly detected even .when produced at a relatively great distance from the vessel equipped with my apparatus.

Another object of the invention is to provide an apparatus of this character, embodying among other features, an element such as a wire or string which is adapted to be tuned to correspond with the frequency or eriodicity of a sound or sounds emitted under the water, so that such sound or sounds may be instantly and readily dctected, and in some instances their proximity or remoteness located. 1

With the above recited objects, and others of a similar nature in view, my invention consists in the construction, combination and arrangement of parts set forth in and falling within the scope of the appended claims. Q

In the accompanying drawings- Figure 1 is a vertical cross-sectional view taken through a portion of the hull of a vessel and showing a preferred form of my sound-detector applied thereto, certain parts of the detector being shown in elevation and certain parts in section.

Fig. 2 is a similar vlew, but ShOWlIlg the ly pro-' nally vibrating wire-or string element of the apparatus assecured directly to the hull' of the vessel nstead of to a separate diaphragm.

Fig. 3 1s a v ew, somewhat diagrammatically, of a further modified form of the invention and showin the employment of'a m crophone 1n circuit between'the string or wire and the telephonereceiver.

F g. 4 is a similar view of another modi ficatlon wherein the transverse force on the w1r e or string is exerted by a diiferent magneticdevice.

Fig. 5 is a similar View of'still another mod fication in which the detector wire and the pmmary circuit of the telephone receiver are in parallel in the batter-y circuit, with a choke coil in the latter.

Referring now to the accompanying drawings in detail, the letter A indicates conventionally a portion of the side of the hull Patented Mar. 15, 1921. i

, of'a vessel, and which below the water line is provided with a relatively small bore oropemng, a.

Surrounding this'opening at the outside of the hull is a water-tight gasket 1, carrya thin membrane 2, preferably of metal.

To the center of this membrane, as at 3, is

attached one end of a wire or string 4, which is preferably made of brass or phosphorbronze, this wire somewhat resembling an ordinary piano wire. Such wire is threaded through the bore, a, in the hull of .the vessel and at its inner end is attached to a suitable sliding or reciprocating weight 5, which is shifted, or pulled by means of a coil spring 6, one end of which is connected to the weight as at 7, while the opposite end of the spring is connected as at 8 to arectangular block 9 sliding in a correspondingly shaped bore 10of the bearing 11. The weight 5 serves as an inertia means to limit the vibration of the wire to the wire itself. This sliding block 9 is provided with' a longitudithreaded bore 12, inwhich works the screw shaft 13, the outer end of this shaft being journaledin the bearing 14, and such shaft is further provided with a worm-gear 15 meshing with the worm pinion 16 driven by a small electric motor, conventionally running, the rectangular sliding block 9 is moved or shifted slowly and periodically, for example during one-mlnute periods, to-

at will, and is reversed periodically by a suitable automatic switching mechanism which is conventionally shown in Fig. 1, and is indicated as an entirety by the letter S. In this connection it is to be understood that any switching mechanism known in the art, and adaptable to this purpose may be employed. For example, I have shown in Fig. 1 an adaptation of the switching mechanism shown in the U. S. patent to 'Louis, No. 777,116, dated December 13, 1904. It will be seen by reference to Fig. 1, that in adapting the Louis switch to my apparatus the arm h is made rigid with the sliding block 9 and projects through the .slot 11 in the bearing 11. The arms B and B support the guide rod 6 and on this guide rod are two helical springs s and s which are connected at the inner side of the lugs of stops ff mounted on the sliding or movable rod 91. which slides in the arms B--B and is connected atone end to the reversing switch K. The arm k carries a slide piece If and as the arm reciprocates this slide piece at the ends of its strokes strikes the springs s and s", compressing the latter and the resiliency of the springs being communicated to the sliding rod 12., actuates the latter with rapidity to throw the switch K, the direction of the throw of the switch of course depending upon which spring is struck, This double-throw reversing switch K is connected in a single series circuit with the motor in a well known manner. I-have but briefly described the construction of this switcharrangement as of itself it formsno part of the present invention and is merely shown and described sufficiently to illustrate its application. Of course, as above indicated, any suitable switching mechanism known to the art can be employed for this purpose.

By the arrangement shown herein, the varying and progressive tension applied to the .Wire or metallic spring 4 will tune the latter up through a wide range or scale varying from a low pitch to a higlr pitch by a relatively slow movement during periods of-one minute each'for example, and if the membrane 2 to hich such wire or string is attached, and which may be considered as in the nature of a sounding board, is struck by a submarine vibration of the same frequency as that corresponding to a tension of the wire or string, or attuned thereto,

such Wire or string will have a tendency to vibrate in unison with such submarine vibration, provided there be exercised upon the wire a transverse force,that is to say, a force tending to move the string transversely of its length. As shown in Fig. 1, this transverseforce is obtained by placing the wire or string 4 in an air-gap 17 of a powerful electromagnet 18 and passing the electric current through the wire or string by means of a suitable electric battery 19, in circuit with the former.

This of course, will tend to draw the wire or string out of the air-gap by the well known motor action. The reason for the force that tends to draw the strin of wire out of the air-gap lies in the fact t at a circular magnetic field is setup exterior of the conductor, because of the passage of an electric current therethrou h. This circular electric field interferes wlth the electric field set up in the air-gap of the magnet. The lines of force of the field set up around the wire will be either clock-Wise or counter clockwise and accordingly will reinforce the lines of magnetic force in the field of the magnet on either one side or the other. On the side upon which the reinforcing action occurs, there will be exerted a pressure tending to push the wire or conductor out of the magnetic field. This constant transverse force acting upon the conductor causes the conductor to vibrate transversely rather than longitudinally on being set in vibration by the diaphragm. r

I I might here mention that this transverse force on the wire or string can also be obtained by the action of a magnet on a steel wire or string, as hereinafter described in connection with the modified form of the invention shown in Fi 4.

Referring again to ig. 1 of the drawings, the electric circuit includes the battery 19, wire 19, the telephone transformer T with receiver R, wire 20, diaphra m 3, wire or string 4, block 5, and wire 5 and an electric current from the battery 19 is passed throu h the rimary 20 of the telephone trans ormer whose secondary 21 is connected tothe telephone'receiver B. When the string vibrates, ever so little, in the airgap of the magnet, alternating electromovtive forces, induced in the wire by such vistring perpendicularly toward the poles of 5 sequently can only ratifies ship, as'will 'beclearly understood by reference to-Fig. 1, and by comparing. t e intensity of the sounds arriving at each of the corresponding telephone receivers, the approximatedirection of the source of sound may be ascertained and determined, and this is of course a manifest advantage, especially when the vessel is navigating in dangerous or ,hostile waters.

In Fig. 2 I have shown aslightly modified form of the invention. In this instance,

instead of passing the wire or string through a port or opening in the side of the vessel and fastening it to a diaphragm, I attach one end of the string as at 3 directly to the hull A of the vessel and lead the string or wire through the air-gap 17 of the magnet 18' and apply the tension on'the wire at stated periods in the same manner as described for Fig. 1. This arrangement may be adopted in such instances where the plating of the vessels hull is thin enough and of such material as to answer the purpose.

. In Fig. 3 I have shown a further modified form of the invention, and in this instance the vibrations of the wire or string are not transmitted to the telephone receiver R by means. of the induced alternating electromotive force, but by means of a microphone placed in circuit between the string or wire and the telephone receiver. The microphone effect is obtainedb'y means of a slight electric contact taking place at 23 on the wire or string is now exerted,

not by electromotive means, but by a purely magnetic device. The string in this instance is made ofsteel and over it is placed a magnet 25 which exerts a force or tension onv the string tending to pull such the magnet as far as will be permitted by the length of the stringj Referring again to .the form of the invention shown in Fig. 1, it is necessary that the electric circuit containing the wire or string, and the primary of the telephone transformer be of yery low resistance, for the induced electromotive forces due to the vibrations of the string are very small and con- Eroduce appreciable current variations if t ey work in a circuit of very" low resistance. It is for this reason that the battery in Fig. 1 should be preferably athermo-cell battery, which as 1s well known, has both low resistance and low voltage. Such low voltage is an advanta e in this instance, as otherwise there would is a too heavy continuous current passing from the battery through the low resistance of. the wire or string.

In the modification shown in Fig. 5 however, I have illustrated a preferable arrangement in the wiring, because it will permit the use of any ordinary battery cell.

' In this form of the circuit a battery 22' .is connected through a resistance 27 with the conductor 4. In shunt with this circuit is the circuit containing the coil 20 of the primary of the telephone transformer. The resistance 27 is made either high or low depending upon the electro-motive force of the battery 22 so that the exact, correct amount of electricity will flow through wire 4 and the shunt circuit containing the primary 20 of the telephone transformer to insure the maximum efliciency of operation. The correct amount of resistance 27 to obtain the best result with each particular battery 22 may be determined by experiment.

In the circuit containing the cell I have also placed a reactance or choking coil 26. so that the induced electromotive force in the string 4 forces these current variations only and entirely into the circuit containing the primary of the telephone transformer.

The current'flows from battery 22 through resistance 27, which as previously explained is suitably adjusted, through a reactance or choke coil 26, through wire 4, and likewise through the shunt circuit containing the primary 20 of the telephone transformer and back to the battery. Upon wire 4 being set in vibration to cut the magnetic lines of force set up within the magnetic field as previously explained, an induced electromotive force will be set up in the wire 4. This induced el'ectro-motive force will be alternating in character because its value depends upon the speed with which the lines of magnetic force are cut by the wire and this, of course, depends upon the tone to which the wire is adjusted. In other words, there is an alternating current corresponding to the period of vibration of the wire induced in the wire. This alternating current. will be checked from flowing in the circuit including the reactance coil 26 because of the great resistance that reactance coils have to alternating currents, but it will be allowed to flow unchecked through the shunt circuit containing the primary 20 of the telephone transformer, and hence sounds will be producedin the telephone receiver R by reason of the connection between secondary 21 of the telephone transformer and the primary 20.

- means whereby its pitc The operation of the apparatus shown in Fig. 5, is substantially the same as that of the apparatus illustrated in Fig. 1.

If desired the telephone receiver may be used in connection with the well known audion amplifier substantially as is done in wireless telegraphy, in order to amplify the produced electric current variations, before passing them through the telephone.

While I have herein shown the'apparatus attached to the hull of the vessel, it will of course be understood that it may be otherwise associated or employed in connection with the latter.

What I claim is- 1. In a sound detector, a receiver, means for transmitting audible tones or sounds to the receiver, and means for automatically attuning the transmitting means in a range or scale up and down between a relatively low pitch and a relatively high pitch.

2. In a sound detector, a receiver, and means for transmitting submarine tones or sounds to the receiver, said means including, a vibrating element, means for automatically increasing and decreasing the tension to said element, and means for exerting a transverse force on the element.

3. In a sound detector, a receiver, transmitting means for transmitting submarine tones or sounds to the receiver, including a vibrating wire, and means for automatically and progressively attunin the transmitting is successively raised and lowered.

4. In a sound detector, a receiver anda transmitter, electric circuits in which both the receiver and transmitter are interposed, the transmitter circuit including a vibrating wire under tension, and means for automatically increasing and decreasing the tension of the vibrating wire.

5. In a sound detector, a,receiver and a transmitter, electric circuits in which both the receiver and transmitter are interposed,

the transmitter circuit including a vibrating wire under tension, and means, including: an operating electric motor, for increasing and decreasing the tension of the vibrating wire.

6. In a submarine sound detector, a receiver, a diaphragm transmitter, electric circuits in which both the receiver and trans mitter are interposed, the transmitter circuit including a vibrating wire under tension, means, including an operating electric motor, for increasing and decreaslngthe.

and a tension of the vibrating wire, magnetic device for applying a transverse force to the wire. 1

7. In a sound detector, a receiver, a sound transmitting diaphragm, electric circuits in which both the receiver and the transmitting diaphragm are interposed, the diaphragm circuit including a vibrating wire under tension, and means, including an operating electric motor, for automatically increasing means comprising a spring controlled weight and a motor for operating the same for applying variable tension to said element, and means for exerting a transverse force on the element. L

10. Ina submarine sound detecting apparatus, a receiver,"and means for transmitting submarine sounds or tones to the receiver, said means including a vibrating string or wire, a weight connected therewith, a spring exerting tension on said weight, a slidable member connected with said spring, and a motor for imparting a sliding movement to said member, and means for exerting a transverse force on the element. r

11. In a submarine sound detecting apparatus, a diaphragm, a string or wire connected at oneend with said diaphragm, a

sliding member resiliently connected with the other end of the wire adapted to tension the same, and a motor for periodically imparting movement to the sliding member.

12. In a submarine sound detecting apparatus, a diaphragm, a string or wire connected with said diaphragm, means for applying variable tension to said string or wire, and means for applying a transverse force to the string or wire, said latter means includ ing a magnetic element located adjacent the string or wire and an electric battery in circuit with the .string or wire and adapted to pass an electric current through the latter.

13. In a submarine sound detecting apparatus, a plate-like member forming a section of the hull of a vessel, a string or wire connected with one end of said member, a resilient member connected with the opposite end of said string or wire, means operating on said resilient member to automatically apply variable tension to the wire, and means for exerting a transverse 'force on the wire.

14. In a submarine sound detecting apparatus, a plate-like member forming a section of the hull of a vessel, a string or wire connected with one end of said member, a resilient member connected to the opposite netic device for applying a transverse force In testimony whereofI aflix my signature to the wire, and a receiver located in an elecin the presence of two witnesses. tric circuit with the wire. e

15. In a sound detector,,a transmitter au- THEODORE BO'DDE.

5 tomatically attuned to vary its pitch up and Witnesses: I

down between a relatively low and a rela- MAUDE R. PEARSON,

tively high pitch and a receiver. JENNm M. RAMSDEN. 

